In a production procedure of a semiconductor device, a testing apparatus for conducting a test on a finally produced IC chip or other electronic device is necessary. As one kind of such testing apparatuses, there is known an electronic device testing apparatus for conducting a test on an IC chip under a normal temperature, a higher temperature condition or a lower temperature condition than the normal temperature. It is because, as characteristics of an IC chip, it is required to guarantee to operate well at a normal temperature, a high temperature and a low temperature.
In an electronic device testing apparatus of this kind, the testing environment is brought to be a constant temperature environment at a normal temperature, high temperature or low temperature, then, IC chips are conveyed to above a test head, where the IC chips are tested by being pressed against contact terminals of the test head and brought to electrically contact with them. From the test as above, the IC chips are preferably tested and classified to at least good ones and defective ones.
However, as IC chips become higher at speed and more highly integrated in recent years, self-heating value at operation tends to increase, and such a self-heating value tends to increase also during the test. For example, there are IC chips generating tens of watts of self-heating depending on the kind, so that a temperature range is remarkably wide between the case without self-heating and the case with self-heating.
Therefore, when conducting a high temperature test, for example, at 150° C. or so, heat due to self-heating generated by IC chips is added to this heat quantity and a correct test evaluation becomes difficult in spite of conducting test under a constant temperature environment.
A method of providing a sensor for detecting a temperature of IC chips immediately close to the IC chips and feeding-back an actual temperature of the IC chips detected by the sensor to a temperature applying device has been proposed (the patent article 1). However, there is a limit even though providing a temperature sensor immediately close to IC chips and heat resistance between the IC chips and the temperature sensor cannot become zero. Accordingly, a true temperature of the IC chips cannot be detected as far as using an external sensor.
Also, as a technique for maintaining an IC chip temperature which changes momentarily by self-heating to be in a test temperature range, there is a proposal of bringing a temperature control device provided with a heating function and a cooling function to contact with an IC chip (the patent article 1). However, a heat capacity of IC chips in downsizing trends and a heat capacity of the temperature control device were too far different, so that there was a problem that even the feedback control by a temperature control device cannot follow a temperature change by self-heating of IC chips.    [Patent Article 1] The U.S. Pat. No. 6,476,627